The first laparoscopies were already published in 1944 by Hans Frangenheim and Raoul Palmer. However, Kurt Semm is considered to be the pioneer of the laparoscopic or pelviscopic operations, as his then spectacular procedures and inventions revolutionized surgery and, notwithstanding much hostility, became established in the preceding century by the middle of the seventies.
In the meantime, the overwhelming number of procedures in endoscopic and laparoscopic surgery is conducted minimally invasively. This affects all disciplines that involve active operations. The term “minimally invasive” or “keyhole surgery” designates operation techniques via the smallest access using instruments and cameras specially developed for this. Trocars are standard instruments in minimally invasive surgery whose use includes special features and risks.
The trocar is an instrument, sharp or blunt, with the aid of which during surgery an opening is created as an access to the body cavity following a previous skin incision. In general, the abdominal cavity is thereby previously inflated using pre-warmed CO2 in order to create better visual possibilities. This is held open using a trocar sleeve. This is generally a trocar pin, which, having an inner diameter of e.g. 3.0-12 mm, sits in the trocar sleeve, and whose point closes the opening in the trocar sleeve. The trocar is inserted e.g. through the abdominal wall or the navel into the abdominal cavity. The operator then has the possibility, following withdrawal of the trocar pin from the trocar sleeve, of looking through the trocar sleeve using optics (endoscope) or operating minimally invasively within the abdominal cavity using gripping, cutting or other instruments. (The diameters of the instruments are standardized so that trocars and instruments from various manufacturers fit together.) This can take place using a trocar head connected to the trocar sleeve, which has a gas-tight port for the previously listed instruments. Modern trocar systems are made either from surgical steel or medical plastic or a combination of these materials. They are offered as both reusable and disposable instruments. Taking into account the trend is increasingly towards disposable, as the preparation guidelines are becoming constantly more stringent, and trocars, due to their extant hollow spaces, are indexed as semi-critical instruments for reuse. The obturator or trocar pin is fitted to the trocar sleeve and can have a cutting as well as a blunt point. In addition, there are also so-called safety trocars, in which the cutting point is provided with a blade that withdraws after penetrating the abdominal wall in order to prevent injury to the internal organs. The trocar sleeves can have a valve mechanism or connection, which is used for suction, insufflation, etc. According to the prior art, trocar sleeves are available as rigid and flexible, in order to maintain the guiding characteristics for instruments during necessary manipulations with the instruments during the operation.
All minimally invasive procedures, primarily in the region of the abdominal cavity and pelvis, have in common the use of trocars for creating the access into the abdominal cavity and for inserting optics and instruments. Trocars and their daily use have become self-evident in the areas of gynecology, urology and surgery.
Trocar systems are known in the most varied of embodiments as both reusable and disposable systems. They consist in general of a trocar sleeve and a trocar pin moveable within the trocar sleeve, which pin is often equipped with a sharp cutting edge on its distal end for penetrating tissues.
Documents like US 2005/0251190 or US 2007/008827 describe gas-tight access paths using seals and connection systems. Sealing systems are also known from U.S. Pat. No. 4,943,280; U.S. Pat. No. 4,655,752; U.S. Pat. No. 4,978,341; EP 0 567 141, among others. The last named describes a valve system which enables the insertion of surgical instruments into the body of a patient, in particular via a trocar system. A gas-tight closure is guaranteed for instruments of various sizes.
More than 50% of complications take place intra-operatively and thus a fast handling on the part of the operator is necessary to avert life-threatening situations. It thereby occurs precisely in endoscopic operations, that in these extraordinary situations, instruments inserted via the trocar must be exchanged quickly and often. Very often, the trocars currently available on the market do not have the necessary holding function, e.g. in the abdominal wall, and slip out with the instruments. By this means, uncontrollable states can quickly arise, because a complex (time-consuming) new placement is necessary. This stress factor can lead to ongoing complications for the entire operating team. Thus, a trocar would be desirable which held securely in all situations, is atraumatic, has a favorable cost-benefit ratio, and last but not least can be placed and removed easily and without complications according to “surgical thinking.”
Furthermore, trocar systems like the Kii Balloon Blunt Tip System (Applied Medical) are also known, which have an inflatable balloon in the front region of the trocar sleeve. After insertion of the trocar, air is thereby blown into the balloon, whereby this expands and should prevent the trocar from slipping out. The disadvantage in this system is primarily the arrangement of the balloon on the outside of the trocar, by which means the balloon must be guided along with the trocar through the insertion channel, which has proven to be a disadvantage in practical use. In addition, an additional connection has to be provided for the air supply, which generally hampers handling and increases the time for the operator to insert the trocar. Furthermore, the risk exists that the balloon undergoes damage during the operation due to its implementation, which can lead to a failing functionality of the balloon and the risk of the trocar slipping out during the operation.